Medical diagnostic imaging and scanner systems such as magnetic resonance imaging (MRI) apparatus, X-ray machines, positron emission tomography (PET) scanners, and computer tomography (CT) scanners are well known. Such machines are quite popular as a tool for providing images of internal portions of patients for diagnosis of medical conditions, such as internal injuries, cancerous tumors and the like.
Some types of X-ray machines include an X-ray source and an X-ray detector mounted at opposite ends of a C-shaped arm. The C-shaped arm is often attached to a carriage which is displaceable in a horizontal, or longitudinal direction. The C-shaped arm is also rotatable about an axis extending along a center line of the C-shaped arm. The X-ray source and the X-ray detector can thus be adjusted in such a manner that the patient to be treated can be irradiated in all desired directions and from all desired positions. For example, the C-shaped arm is positioned around a portion of the patient sought to be imaged, such as a leg or arm, and then X-rays are directed at that portion of the patient by the X-ray source, pass through the body, and are received by the X-ray detector.
A factor affecting the quality of the acquired images is attenuation of the radiation between the source and the detector, which causes artifacts to be present in the resulting images. An artifact is any distortion or error in the image that is unrelated to the subject being studied. For X-ray CT, artifacts are any discrepancy between the CT numbers represented in the image and the expected CT number based on the linear attenuation coefficient. Artifacts degrade image quality as well as hide areas of pathology, so it is important to prevent them. Metallic objects, such as the metal frame of a patient table, are one cause of image artifacts.
In nuclear medicine, it is common to detect radiation by positioning the detectors at various different angles about the patient's body. Consequently, in certain instances, the table may be between a given detector and the patient's body, thereby causing attenuation of radiation reaching that detector and artifacts in the resulting image. Previous patient support tables provided basic support for the patient but also undesirably attenuated the radiation from the source to the detector. Additionally, some previous patient support tables require separate accessories for certain needs. Such accessories might include armrests, head support, etc.
What is still desired, therefore, is a new and improved patient support couch or table apparatus for use with medical diagnostic imaging and scanner systems. In particular, what is desired is a new and improved patient table which provides substantially unimpeded access for a C-shaped arm, X-ray source and X-ray detector of an imaging machine. What is also desired is a patient table with lowered attenuation that produces fewer and smaller image artifacts.